Sustainable solution selection for solid waste incineration fly ash: a multicriteria framework based on objective weights and fusion ranks

Fly ash (FA), a byproduct of municipal solid waste incineration (MSWI), poses significant hazards to urban development, necessitating its sustainable treatment. This study proposes a systematic decision support tool to identify the most sustainable MSWI FA treatment technology among various options, considering diverse criteria. The research introduces a hybrid Multi-Criteria Decision-Making (MCDM) framework integrating the Grey Relational Coefficient (GRC) into the Analytical Network Process (ANP) for objective criterion weighting. Additionally, a Projection-based Programming (PbP) approach enhances the reliability of ranking MSWI FA treatment alternatives by reconciling disparate sequences from different MCDM techniques. This work pioneers the early application of MCDM methods in prioritizing sustainable MSWI FA treatment, offering two crucial mathematical contributions. Firstly, the GRC-ANP method objectively assigns weights by capturing statistical relationships among criteria. Secondly, the PbP approach consolidates varied MCDM outcomes to provide a reliable ranking. Testing five technologies against eight sustainability criteria validates the robustness and effectiveness of the framework, affirming its potential in aiding decision-making for sustainable MSWI FA treatment solutions.